Navy helping mammals

According to the U.S. Navy's online resource for information concerning sonar and marine mammals, Sonar is for "Sound Navigation and Ranging," Which is using underwater acoustics to know the water depth. This tool is used to know who is underwater so they can defend the nation if there is an attack. There are two types of sonar, passive sonar and active sonar. First, passive sonar it is a listening machine which depends on hydrophonics to receive its amplify; this machine is mainly used to know if there are submarines from the sound of there engines; the best thing about this machine is that it dose not have any sound but it can not detect submarines that work on batteries and that run it run at a low speed. Second, the active sonar work is by sending pulses of sound underwater, that will touch submarines and return back to the machine, which is similar to the echo; this signals will be converted to electronic signals; the signal will tell us which other submarines are close to us, and the speed, and size of the submarine. The best benifit of this machine is to locate and to track other submarines, but it can lead other submarines to now about our location too; this machine which is called mid-frequency sonar is installed in most Navy’s submarines; there are three types of active sonar, first, is a high frequency sonar, which is used to know the water depth, hunting mines and guiding torpedoes. The second is the mid-frequency sonar, which is used to identify and prosecuting submarines; this machine has been used since the second war. Finally, the low frequency sonar, is used for long-range search, and for the surveillance of submarines. This machine is known as the protector of the nation; at the same time the US Navy is doing its best to protect mammals by doing researches to understand how can it affect mammals. The US Navy is trying its best to protect mammals by making there training in the daytime hours if possible. The US Navy should try to depend more on active sonar, and try to depend on the passive sonar; the US Navy should use devices to avoid mammals; and the mid frequency sonar is should be replaced by a new version, which has less effect on mammals.
The US Navy should depend on the passive sonar more than the active sonar because it is less harmful to mammals; this is because the more they use active sonar, the more mammals will die.
The mid frequency sonar is very old; it was used since the second world war, and from that time untill now have been now changes in the machine; so the US Navy should try to make a new machine, which is the same result but is less harmful.
The US Navy should use machines to move whales from the sonar frequency, so they can make the mammals safer. In response, the US Navy should develop their sonar machine; depend on passive sonar more and to use machines that move whales away. Human should rule this world well.
United State Navy (n-d.). retrieved from http://www.whalesandsonar.navy.mil/understanding_sonar.htm http://www.whalesandsonar.navy.mil/marine_mammal_protection.htm http://www.whalesandsonar.navy.mil/index.htm on (13/07/2006)